Punch press mechanism and automatic stop therefor



G. H. LEI-AND `July 4, 1933.

PUNCH PRESS MECHANISM AND AUTOMATIC STOP THEREFOR Filed Nov. 12, 1931 2 Sheets-Sheet l `hlly 4, 1933. K G LELANDV 1,916,379

PUNCH PRESS MECHANISM AND AUTOMATIC STOP THEREFOR Filed Nov. l2, 1931 2 Sheets-Sheet 2 Patented July 4, 1953 Unire stares PATENT orrics GEORGIE H. LELAND, 0F DAYTON, OHIO, ASSIGNOR 0F ONE-HALF TO THE LELAND ELECTRIC CjP-llYy OF DAYTON, OHG, A CORPORATION OF OHIO PUNCH PRESS MECEIANISM Application led November 12, 1931.

This invention relates to punch press mechanism and more particularly to such a mechanism employing progressive dies. Y

One object of the invention is to provide a punch press with means for automatically stopping the press when that portion of the strip which has been operated on by one die is out of line with a succeeding` die.

A further object of the invention is to provide such a press with electrically controlled means for stopping the operation thereof, including an improved Yform of switch.

It is a further object of the invention to provide in connection with a plurality of presses operating in synchronism means tor automatically stopping all the presses it a strip is out of line with a die oi' any one of the presses.

Other objects of the invention will appear as the apparatus is described in detail.

in the accompanying drawings 1 is a side elevation ci a pair oi presses connected one with the other for synchronized operation, one oi the presses being partly broken away; Fig. 2 is a plan view, partly broken away, of a strip or" material showi the operation of the successive dies thereon; Fig. `B a sectional detail view of the switch which controls the operation ci the press; Fig. 4 is a plan view ci: the switch; 5 is a diagram of the circuit tor the press controlling` device, and F ig. 6 is a detail view oit the clutch mech anism.

In these drawings l have illustrated one embodiment oi my invention and-have shown the same in connection with presses oiA a well known type but'it will be understood that the invention may take various forms and may be applied to presses oi' various kinds.

The mechanism here illustrated comprises two punch presses, 1G and 11, each ot which is complete in itself and consists of a bed plate 12, mounted on the main trame, and a ram 13 movably mounted on that frame for movement toward and from the bed plate, the die members being carried respectively by the bed plate and the ram. The two presses are operated in synchronism from a common electric motor le which is connected by belts orchains 15 with drive wheels 16. he drive AND AUTOIMATC STOP THEREFOR Serial No. 574,549.

wheels are connected with the respective rams through the usual driving mechanism, which embodies a spring retracted clutch. This clutch is controlled by a foot lever 17 which, when depressed, serves to connect the driving wheel with the ram and which, when elevated, releases the clutch to permit the separation of the elements thereof to inter rupt the connection between the driving wheel and the ram. This connecting member may be of any suitable character and is here shown as comprising a spring operated clutch. In the particular arrangement illustrated the driving wheel 16 is rotatably mounted on the shaft and this wheel carries one member 76 of a clutch. The other member 77 of the clutch is slidably mounted on and splined to the shaft and is provided with an extension 7 S. The clutch member and its extension are provided with longitudinal bores 79 in which are slidably mounted studs 80 carried by a supporting member 81 mounted on the shaft and held against axial movement, as by contact with a 'bearing 82 in which the shaft 7 5 is mounted. Springs 83 mounted in the bore 79 actagainst the studs 8O to move the clutch member 77 toward the clutch member 7 6 and thus serve normally to maintain an operative connection between the driving wheel and the operative parts of the machine, with which the shaft 7 5 is connected. For the purpose of retracting the clutch member 77 the eX- tension 7 8 of that clutch member is provided with a peripheral cam 84 and a trip device, such as a plunger 85, is mounted for movement into and out ot' the path of that cam. In the present construction the plunger is slidably mounted in a bearing 86 and is acted upon by a spring 87 which tends to move the same into the path of the cam. rlhe plunger is connected by a link 88 with the toot lever 17. When the foot lever is retained in its depressed or operative position the plunger' will be out of the path of the cam 84 and the clutch will be set to establish operative connection in the driving mechanism and operative parts of the `machine. lVhen the lever 17 is released the plunger will be moved into the path of the l0@ cam which will engage the same and retract the movable clutch member and thus interrupt the operative connection bet-ween the driving mechanism and the operative parts of the machine. Ordinarily the clutch controlling lever 17 is held in its depressed position, to maintain the connection between the driving wheel and the ram, by means of a manually operated latch but, in the present device, l have substituted for the latch an elcetro-magnet 18 the armature 19 ot which is carried by the lever 17 and will, when the magnet is energized, retain the lever in its depressed position, after it has once been moved to that position, thereby permitting the automatic control of the press.

Each press is provided with a feeding-in device which in the present instance comprises a lower roller 2O and an upper roller 21, and a feeding-out or ejecting device which is shown as consisting of a lower roller 22 and an upper roller 23. These feed rollers are actuated by a rack bar 24, the respective end portions of which mesh with pinions 25 secured, respectively, to the lower rollers 20 and 22 by means of pawl and ratchet mechanism, not shown, which will cause the rollers to be actuated when the rack bar is moved in one direction but will permit the same to remain stationary when the rack bar moves in the other direction. The rack bar is actu ated by a rock arm 26 having a slot 27 through which extends a crank pin 28 driven from the operating mechanism and, in the present instance, carried by a cam disk 29. In order that the strip may be shifted to aline the same with the dies the upper rollers of each pair are mounted for movement into and out of engagement with the strip, this movement being so controlled that the rollers will be moved to their inoperative positions as the ram moves downwardly and will be moved into their operative positions if the ram moves upwardly. As here shown, each upper roller is supported in the ends of a pair of arms 30, one only of which is shown, and these arms are pivotally mounted between their ends and are connected by links 31 with levers 32 pivotally mounted between their ends on the frame of the press above the cam disk 29. The inner ends of the levers are arranged or engagement by a plunger 33 which is actuated by the cam 29, the cam being ar anged to impart movement to the rollers at the proper time with relation to the movements of the ram. The feeding rollers and their operating mechanism are of a well known type and form no part of the present invention. The strips may be delivered to the feeding rollers, and the operation of the rollers thereon controlled, in any suitable manner but the present mechanism is well adapted for use with the automatic strip delivery mechanism shown in my copending application liled November 9, 1931, Serial No. 573,785, and with the -feed roller controlling mechanism shown in my copending application filed November 16, 1981, Serial No. 515,324.

In the construction here illustrated each press is provided with two or more progressive dies, the several dies being adapted to operate successively on the same portion of a strip of material. After the dies ot the first press operate on the strip it is conducted through a chute 34 to the second press and the portion which has been operated upon is alined successively with the dies of that press, so that the strips are fed progressively through the two presses and the several operations completed, the arrangement and operation of the synchronously operating presses corresponding substantially to those shown in my co-pending application filed November 19, 1931, Serial No. 576,025.

The presses of the present mechanism are equipped with dies for performing live operations. The first press having a two stage die and the second press having a three stage die. These particular dies are designed to strike ffom a strip of metal the armature laminations and the stator laminations or rings for an electric motor, the stator lamination being Jformed from that part of the strip which surrounds the portion from which the armature lamination is formed. In Fig. 3 I have shown a .strip in the condition in which it would be at the end of any operative movement of the ram after the strip had been fully inserted in both presses, it being understood that the several dies will operate simultaneously upon different portions of a long strip, when the latter is in an intermediate position. Then the strip is first inserted into the first press the first stage die 35 will punch the slots 36 and shaft opening 37 of an armature lamination in a portion of the strip lying approximately midway between the lateral edges thereof. It will also punch the bolt holes 88 for the stator lamination or ring. The strip is then advanced to the second stage die 39 and is properly alined therewith, this being preferably accomplished by the usual pilot pins carried by the ram and entering two diagonally opposite bolt holes 88 which have been previously formed in the strip. 'l` his alining operation takes place during the initial movement of the ram and the further movement of the same will cause the second stage die 89 to form the slots #i0 for the stator laminations in that part ol" the strip which surrounds the slots 3G. The strip is then advanced through the chute 34 to the second press and that part thereof. which has been operated upon by preceding dies is properly alined with the first stage, die il of the second press and this die punches out the armature lamination and causes the same to be delivered from the press. The strip is then advanced to the second stage die 42 of ist the second pi'ess and this die removes a narrow portion of the metal from the inner edge .of the stator lamination to provide the clearance or air gap between the stator and armature in the iinished motor. The strip is then againradvanced and alined with the third stage die d3 of the second press which strikes out the completed stator lamination, whiclnin the present instance, is approximately rectangular in shape-as shown by the opening #lll which is thus formed in the strip. Ordinarily the strips are of such length that at one time during the progress of a strip through the two presses it will be simultaneously acted upon by all the dies, but this is not essential as the strips follow one another through the press and during other periods of operation one press will be operating on one strip and another press on another strip.

lt sometimes happens, even when proper alining devices are employed, that the ope-nings formed in the strip by al preceding operation will not be correctly alined wit-h a succeeding stage die. lf the strip is'substantially out of line with the die those portions thereof which are inline with the die will be stamp-ed out and the blank ruined butif a wall of an opening in the strip projects very slightly beyond the edge of the die th-e die will not sever this portion vbut it will be bent into the lower die and the upper die will be slightly displaced, thus causing its opposite edge to engage the lower die, which engage` nient may result in a serious injury to the dies. To avoid the possibility ofthis injury to the dies, generally known as shearing, I have provided means for automatically stopping the press whenever the strip isout-of proper alinement with a succeeding die'. T he mechaiiism for thus controllingthe operation of the press may talreivarious forms but it is preferably electrically operated and includes a switch which iscontrolled by theposition of the strip withV relation to the die. As has L4een above explained the connectionbetween the driving mechanism and the ramis controlled by the magnet 18 which', when energleed, holds the clutch operating lever 17 in its depressed or operative position. and l have connected in circuit with this-magnet a switch which isfprovided with a. strip controlled actuating device, this actuating device being of suoli a character and so arranged that when al previously formed opening in the strip is in line therewith the actuating device will inove through that opening without disturbing the switch but if the opening is slightly out of line with the actuating device it willwhe engaged by the latter and the yswitch operated to break the circuit through the magnet. The switch may beef any suitable character and may be arranged in any suitable location. Preferably both the switch and its actuating device arecarried by the rain and, as here shown, the ram is provided with a recess 45 in which the switch is located. rl`he switch comprises two stationary contact membeis 4G secured to a plate of insulating material 47 y arranged within the recess 45. The movable Contact member of the switch consists of a contractile band of conducting material, such as a coiled spring 4S, which is movableinto and out of engagement with the lined Contact members lG.k The actua-ting device for the switch is shown as a plunger i9 which. in the present insta-nce, extends through the die which is carried by the rain and into an opening 50 formed in the rain beneaththe recess 45 and in line with the movable cont-act ine1nber 48. This plunger is provided with a head 5l, connected therewith by a stem of insulating material 52, and having` tapered portions of the head are of a diameter Yless than the normal interior diameter of the contact spring 48 and will pass freely through the same but the intermediate portion of the end portions. The smaller ends of the tapered A y head is of greater diameter than the normal internal diameter of the Contact spring. The

head is so connlctedwith the plunger when the latter is in its lowermost position the upper portion of the tapered end 53 will be pressed into the annular spring, which will be slightly expanded and will be supported r by the head in engagement with the contact members 46, thus maintaining the circuit closed through the Vmagnet so long as the plunger is in its normal position. lhen the plunger is moved upwardly the intermediate portioii of the head, that is. the portion of greatest diameter, is forced through the spring,'the adj acent ends of the liXed contact member l0 being shapedyto permit the ypassage of the head, and the spring will contract about the lower tapered end portion 54 of the head and will thus be forced downwardly out of engagement with tlieviX-ed contact members, thereby breaking the circuit and deenergizing the magnet. lt will be apparent that the shape ofthe head is such as vto positively retain the contact spring-in the 'it may be specially formed opening. The

plunger snugly in this opening but will movefreely therethrough when the strip is properly positioned but if the strip is not iro ierlv ositioned and the o ienine' is even.

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slightly out of line with the plunger the latter will engage the edge of the-opening and will be forced upwardly with relation to the ram by the continued downward movement of the ram, thereby causing the head 51 to open the switch. It desired, a light spring may bc provided to hold the plunger normal-ly in its lower-most position but when used this spring will be so li `eht that it will not appreciably retard the movement of the plunger. `When two presses are operated in synchronism as above described cach is provided with an automatic switch and the two switches are connected in series with the controlling magnets for both presses, as shown in Fig. 5, so that when either switch is open both magnets will be dcenergized and both presses stopped.

I have also provided means for automatically stopping the press if superimposed strips, or a strip or excessive thickness, are presented to the first press. This is accomplished by connecting in the magnet circuit, in series with the above described switches, a third switch and providing means controlled by the thickness of the strip to open the third switch. The strip controlled mechanism for opening this third switch may take various forms but I have here shown a device similar in construction and operation to the strip controlled device illustrated in connection with the automatic feeding mechanism shown and described in my application for patent Serial No. 57 5,324,1iled November 16. '1931. This device comprises a bracket 55 pivotally mounted at one edge of a eed table 56 over which strips are delivered to the feeding-in rollers 2OY and 2l. The bracket has an upper portion extending above the table and provided with a roller 57, and a lower portion 58 extending below the table. An armv 59 is pivotally mounted between its ends on the lower portion 58 of the bracket and'carries at one end a roller 60 which extends through .an opening 61 formed in the table directly beneath the roller 57. The other end of the arm 59 carries a contact member 62 which is held normally in engagement with second contact member 63 carried by a plate 64e secured to the bracket 55, and these two contact members are connected in circuit with the magnet. A rod 65 is secured to the arm 59 adjacent to the contact member 62, extends through an opening` in the plate 64 and is provided at its lower end with a head 66. A spring 67 coiled about the rod is coniinedbetween the .head 66 and the plate 64, holds the contact member 62 normally in engagement with the contact member 63 and when these contact members are in engagement the rollers 67 and 60 will be spaced apart a distance sufiicieir` to permitthe passage of a strip of ordinary thickness. `The spring 67 is of suiiicient strength to hold the arm normally against movement with relation to the bracket. In the normal operation oi. the device the arm and the bracket will move in unison without separating the contacts 62 and 63. Should two superimposed strips or a strip of excessive thickness bc introduced betwen the rollers 57 and 6() the bracket 55 will be moved upwardly about its axis, the lower roller 60 will fulcrum on the lower surface of the strip and the upward movement of the lower part of the bracket will cause-the arm 59 to move about its axis and thus separate the contacts 62 and 63 and break the circuit through the magnet. As a matter of convenience I have inserted in the maglnet circuit of each press a manually operated switch 70, whereby either or both presses may be stopped independently of the automatic mechanism.

Vhile I have shown and described one embodiment oi my invention I wish it to be understood that I do not desire to be limited to the details thereof as various modifications may occur to a person skilled in the art.

Having now fully described my invention, what I claim as new and desire to secure by Letters Patent, is:

l. In a punch press comprising a ram having means to support a die member for operation on a. strip of material having a previously formed opening therein, and means to interrupt the operation of said ram; a plunger yieldably mounted on said ram and arranged to pass through said opening when said strip is properly positioned with relation to said die and to engage said strip and to be actuated thereby when said strip is improperly positioned with relation to said die, and means controlled by the movement or said plunger to operate Said interrupting means.

2. In a punch press having al die to operate on a strip of material having a previously formed opening therein, electrically operated means to control the operation of said press, a switch in circuit with said electrically operated means, and an actuating device for said switch mounted for movement with said die and having a part arranged to pass through said opening when said strip is properly positioned with relation to said die and to engage said strip and aetuatesaid switch when said strip is improperly positioned with relation to said die.

3. In a punch press comprising a ram having means to support a die member for operation on a strip of material having a previously formed opening therein, electrically operated means to control the operation of said ram, a switch carried by said ram and connected in circuit with said electrically operated means, and an actuating device for said switch supported by said ram for movement therewith and for movement with relation thereto, said actuating device having a part to pass through said opening when said strip is properly positioned with relation to said die and to engage said strip and cause said switch to be actuated when said strip improperly positioned with relation to said A 4. In a punch press, a ram, a plurality of die members carried by said ram to operate successively on a given portion of a strip of material, electrically operated means to control the operation of said ram, a switch in circuit with said electrically operated means, and an actuating device for said switch carried by said ram and arranged to pass through an opening formed in said strip by a preceding die member when said opening is in a predetermined position with relation to a succeeding die member and to engage said strip and cause said switch to be actuated when said opening is not in said predetermined position.

5. n a punch press comprising a ram having means to support a die member for operation on a strip of material having a previously formed opening therein, means including an electro-magnet to control the operation of said ram, a switch in circuit with said magnet, and an actuating device for said switch supported by said ram for movement therewith and for movement with relation thereto, said actuating device having a part arranged to pass through said opening when said strip is properly positioned with relation to said die and to engage said strip and cause said switch to be actuated when said strip is improperly positioned with relation to said die. f

5. ln a punch press comprising a ram havin g means to support a die member for operation on a strip of materialhaving a previously formed opening therein, and means including a 'lever to ,control the operation of said ram; an electro-magnet to hold said lever normally in its operative position, a normally closed switch in circuit with said magnet, lan actuating device for said switch supported by said ram for movement therewith and for movement with relation thereto, said actuating device having a part arranged to pass through said opening when v said strip is properly positioned with relation to said die and to engage said strip and cause said switch to be actuated when said strip is improperly positioned with relation ycomprising {iX-ed contact members connected in circuit with said electrically operated means, and a contact member movable into and out of engagement with said iiXed contact members, a plunger carried by said ram and having a part arranged to pass through said opening when said strip is properly positioned with relation to said die and to engage said strip and to be actuated thereby when said strip is improperly positioned With relation to said die, and a part connected with said plunger tok control the position of said movable Contact member.

8. ln a punch press comprising a ram having means to support a die member tor operation on a strip or' material having a previously :torined opening therein, electricallyoperated means to control the operation oi said ram, a switch carried by said ram and comprising hired contact members connected iii circuit` with said electrically operated means, an expansible Contact member having an opening therethrough and movable bodily into and out ci' engagement with said lined contact members, a plunger carried by said ram and having a part arranged to pass through said `opening' when said strip is properly positioned with relation to said die and to engage said strip and tobe actuated thereby when said strip is improperly posi'- tioned with relation to said die, and a meinber connected with said plunger for movement thereby and arranged to engage said cxpansible contact member and hold the saine in engagement with said iiXed Contact members when said plunger is in its normal position and to expand said expansible contact member and cause the same to move out of engagement with said contact members when said plunger is actuated by contact with said strip.`

9. ln a punch press comprising a ram having means to support a die member for operation on a strip of material having a previously lorn ed opening therein, electrically operated means to control the operation oic said ram, a switch carried by said ram and comprising i'ixed contact members connected in circuit with said electrically operated means, acontractile band of conducting material movable into and out of engagement with said fixed contact members, a plunger carried by said rain and having a part arranged to pass through said opening when said strip is properlypositioned with relation to Asaid die and to engage said strip and to actuated thereby when said strip is improperly positioned with relation to said die, and a head connected with said plunger and having' its upper and lower portions tapered-in opposite directions, the intermediate portion oi said head being of a diameter greater than the normal internal dia noter oit said contractile band, said head being so arranged vthat when said plunger is in its nor- ;'nal position the upper tapered portion of s; id head will enter said contractile band and support the saine in engagement with said lised Contact members and when up ward inoveu'ient is imparted to said plunger the intermediate portion of said head will be forced through said band and the band caused to engage the lower tapered portion of said head and to be moved out of engage: ment with said tixedcontact members.

l0. A punch press mechanismcomprising a plurality ol presses having diesrto act pro'- gressively on strips otmaterial ted successively thereto, means for operating said presses in synchronism, means for transferring said strip from one press to another,

`and strip controlled means to stop both nected in series with the electrically ope 1ated controlling means of both presses, and strip controlled actuating` devices for said switches mounted on the respective presses.y

l2. A punch press mechanism comprising two presses each having a ram, die members mounted on the respective rams to operate successively von a given portion of a strip ot material, vmeans to operate said rams in synclironism, means to advance the strip from one press to the other, separate electrically operated means to control the operation ot therespective rams, switches carried by the respective presses and connected in series one with the other and with both electrically operated means, and actuating devices for said switches carried by the'respective rams, each actuating device having a part arranged to pass 'through an opening previously formed in said strip vwhen said portion of said strip is properly positioned with relation to the die of the press on which that actuating device is mounted and to engage said strip and to be actuated thereby when said portion oi said strip improperly positioned with rc lationto said die.

lntestimony .vhereot, l ailiizmy signature hereto.

GE( RGB H. LELAND.

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